The tutorial section of Apple's website is called Find out how and you can get to it here
. The videos are broken down into categories Mac Basics, Photos, Movies, Web, Music and iWork. Each category has a couple of dozen tutorial videos and a few text tutorials thrown in.
Each video is just a couple of minutes long so you can work through them quickly. The website even puts a checkmark by the tutorials you have already viewed to help you keep track of your progress.
You can find a list of other video tutorials around the web here.